Revert "ARM: tegra: tegratab: dummy change"
[linux-2.6.git] / drivers / acpi / acpica / dsmethod.c
1 /******************************************************************************
2  *
3  * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2012, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acdispat.h"
47 #include "acinterp.h"
48 #include "acnamesp.h"
49 #ifdef  ACPI_DISASSEMBLER
50 #include <acpi/acdisasm.h>
51 #endif
52
53 #define _COMPONENT          ACPI_DISPATCHER
54 ACPI_MODULE_NAME("dsmethod")
55
56 /* Local prototypes */
57 static acpi_status
58 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
59
60 /*******************************************************************************
61  *
62  * FUNCTION:    acpi_ds_method_error
63  *
64  * PARAMETERS:  Status          - Execution status
65  *              walk_state      - Current state
66  *
67  * RETURN:      Status
68  *
69  * DESCRIPTION: Called on method error. Invoke the global exception handler if
70  *              present, dump the method data if the disassembler is configured
71  *
72  *              Note: Allows the exception handler to change the status code
73  *
74  ******************************************************************************/
75
76 acpi_status
77 acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
78 {
79         ACPI_FUNCTION_ENTRY();
80
81         /* Ignore AE_OK and control exception codes */
82
83         if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
84                 return (status);
85         }
86
87         /* Invoke the global exception handler */
88
89         if (acpi_gbl_exception_handler) {
90
91                 /* Exit the interpreter, allow handler to execute methods */
92
93                 acpi_ex_exit_interpreter();
94
95                 /*
96                  * Handler can map the exception code to anything it wants, including
97                  * AE_OK, in which case the executing method will not be aborted.
98                  */
99                 status = acpi_gbl_exception_handler(status,
100                                                     walk_state->method_node ?
101                                                     walk_state->method_node->
102                                                     name.integer : 0,
103                                                     walk_state->opcode,
104                                                     walk_state->aml_offset,
105                                                     NULL);
106                 acpi_ex_enter_interpreter();
107         }
108
109         acpi_ds_clear_implicit_return(walk_state);
110
111 #ifdef ACPI_DISASSEMBLER
112         if (ACPI_FAILURE(status)) {
113
114                 /* Display method locals/args if disassembler is present */
115
116                 acpi_dm_dump_method_info(status, walk_state, walk_state->op);
117         }
118 #endif
119
120         return (status);
121 }
122
123 /*******************************************************************************
124  *
125  * FUNCTION:    acpi_ds_create_method_mutex
126  *
127  * PARAMETERS:  obj_desc            - The method object
128  *
129  * RETURN:      Status
130  *
131  * DESCRIPTION: Create a mutex object for a serialized control method
132  *
133  ******************************************************************************/
134
135 static acpi_status
136 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
137 {
138         union acpi_operand_object *mutex_desc;
139         acpi_status status;
140
141         ACPI_FUNCTION_TRACE(ds_create_method_mutex);
142
143         /* Create the new mutex object */
144
145         mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
146         if (!mutex_desc) {
147                 return_ACPI_STATUS(AE_NO_MEMORY);
148         }
149
150         /* Create the actual OS Mutex */
151
152         status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
153         if (ACPI_FAILURE(status)) {
154                 return_ACPI_STATUS(status);
155         }
156
157         mutex_desc->mutex.sync_level = method_desc->method.sync_level;
158         method_desc->method.mutex = mutex_desc;
159         return_ACPI_STATUS(AE_OK);
160 }
161
162 /*******************************************************************************
163  *
164  * FUNCTION:    acpi_ds_begin_method_execution
165  *
166  * PARAMETERS:  method_node         - Node of the method
167  *              obj_desc            - The method object
168  *              walk_state          - current state, NULL if not yet executing
169  *                                    a method.
170  *
171  * RETURN:      Status
172  *
173  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
174  *              increments the thread count, and waits at the method semaphore
175  *              for clearance to execute.
176  *
177  ******************************************************************************/
178
179 acpi_status
180 acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
181                                union acpi_operand_object *obj_desc,
182                                struct acpi_walk_state *walk_state)
183 {
184         acpi_status status = AE_OK;
185
186         ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
187
188         if (!method_node) {
189                 return_ACPI_STATUS(AE_NULL_ENTRY);
190         }
191
192         /* Prevent wraparound of thread count */
193
194         if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
195                 ACPI_ERROR((AE_INFO,
196                             "Method reached maximum reentrancy limit (255)"));
197                 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
198         }
199
200         /*
201          * If this method is serialized, we need to acquire the method mutex.
202          */
203         if (obj_desc->method.info_flags & ACPI_METHOD_SERIALIZED) {
204                 /*
205                  * Create a mutex for the method if it is defined to be Serialized
206                  * and a mutex has not already been created. We defer the mutex creation
207                  * until a method is actually executed, to minimize the object count
208                  */
209                 if (!obj_desc->method.mutex) {
210                         status = acpi_ds_create_method_mutex(obj_desc);
211                         if (ACPI_FAILURE(status)) {
212                                 return_ACPI_STATUS(status);
213                         }
214                 }
215
216                 /*
217                  * The current_sync_level (per-thread) must be less than or equal to
218                  * the sync level of the method. This mechanism provides some
219                  * deadlock prevention
220                  *
221                  * Top-level method invocation has no walk state at this point
222                  */
223                 if (walk_state &&
224                     (walk_state->thread->current_sync_level >
225                      obj_desc->method.mutex->mutex.sync_level)) {
226                         ACPI_ERROR((AE_INFO,
227                                     "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%u)",
228                                     acpi_ut_get_node_name(method_node),
229                                     walk_state->thread->current_sync_level));
230
231                         return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
232                 }
233
234                 /*
235                  * Obtain the method mutex if necessary. Do not acquire mutex for a
236                  * recursive call.
237                  */
238                 if (!walk_state ||
239                     !obj_desc->method.mutex->mutex.thread_id ||
240                     (walk_state->thread->thread_id !=
241                      obj_desc->method.mutex->mutex.thread_id)) {
242                         /*
243                          * Acquire the method mutex. This releases the interpreter if we
244                          * block (and reacquires it before it returns)
245                          */
246                         status =
247                             acpi_ex_system_wait_mutex(obj_desc->method.mutex->
248                                                       mutex.os_mutex,
249                                                       ACPI_WAIT_FOREVER);
250                         if (ACPI_FAILURE(status)) {
251                                 return_ACPI_STATUS(status);
252                         }
253
254                         /* Update the mutex and walk info and save the original sync_level */
255
256                         if (walk_state) {
257                                 obj_desc->method.mutex->mutex.
258                                     original_sync_level =
259                                     walk_state->thread->current_sync_level;
260
261                                 obj_desc->method.mutex->mutex.thread_id =
262                                     walk_state->thread->thread_id;
263                                 walk_state->thread->current_sync_level =
264                                     obj_desc->method.sync_level;
265                         } else {
266                                 obj_desc->method.mutex->mutex.
267                                     original_sync_level =
268                                     obj_desc->method.mutex->mutex.sync_level;
269                         }
270                 }
271
272                 /* Always increase acquisition depth */
273
274                 obj_desc->method.mutex->mutex.acquisition_depth++;
275         }
276
277         /*
278          * Allocate an Owner ID for this method, only if this is the first thread
279          * to begin concurrent execution. We only need one owner_id, even if the
280          * method is invoked recursively.
281          */
282         if (!obj_desc->method.owner_id) {
283                 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
284                 if (ACPI_FAILURE(status)) {
285                         goto cleanup;
286                 }
287         }
288
289         /*
290          * Increment the method parse tree thread count since it has been
291          * reentered one more time (even if it is the same thread)
292          */
293         obj_desc->method.thread_count++;
294         return_ACPI_STATUS(status);
295
296       cleanup:
297         /* On error, must release the method mutex (if present) */
298
299         if (obj_desc->method.mutex) {
300                 acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
301         }
302         return_ACPI_STATUS(status);
303 }
304
305 /*******************************************************************************
306  *
307  * FUNCTION:    acpi_ds_call_control_method
308  *
309  * PARAMETERS:  Thread              - Info for this thread
310  *              this_walk_state     - Current walk state
311  *              Op                  - Current Op to be walked
312  *
313  * RETURN:      Status
314  *
315  * DESCRIPTION: Transfer execution to a called control method
316  *
317  ******************************************************************************/
318
319 acpi_status
320 acpi_ds_call_control_method(struct acpi_thread_state *thread,
321                             struct acpi_walk_state *this_walk_state,
322                             union acpi_parse_object *op)
323 {
324         acpi_status status;
325         struct acpi_namespace_node *method_node;
326         struct acpi_walk_state *next_walk_state = NULL;
327         union acpi_operand_object *obj_desc;
328         struct acpi_evaluate_info *info;
329         u32 i;
330
331         ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
332
333         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
334                           "Calling method %p, currentstate=%p\n",
335                           this_walk_state->prev_op, this_walk_state));
336
337         /*
338          * Get the namespace entry for the control method we are about to call
339          */
340         method_node = this_walk_state->method_call_node;
341         if (!method_node) {
342                 return_ACPI_STATUS(AE_NULL_ENTRY);
343         }
344
345         obj_desc = acpi_ns_get_attached_object(method_node);
346         if (!obj_desc) {
347                 return_ACPI_STATUS(AE_NULL_OBJECT);
348         }
349
350         /* Init for new method, possibly wait on method mutex */
351
352         status = acpi_ds_begin_method_execution(method_node, obj_desc,
353                                                 this_walk_state);
354         if (ACPI_FAILURE(status)) {
355                 return_ACPI_STATUS(status);
356         }
357
358         /* Begin method parse/execution. Create a new walk state */
359
360         next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
361                                                     NULL, obj_desc, thread);
362         if (!next_walk_state) {
363                 status = AE_NO_MEMORY;
364                 goto cleanup;
365         }
366
367         /*
368          * The resolved arguments were put on the previous walk state's operand
369          * stack. Operands on the previous walk state stack always
370          * start at index 0. Also, null terminate the list of arguments
371          */
372         this_walk_state->operands[this_walk_state->num_operands] = NULL;
373
374         /*
375          * Allocate and initialize the evaluation information block
376          * TBD: this is somewhat inefficient, should change interface to
377          * ds_init_aml_walk. For now, keeps this struct off the CPU stack
378          */
379         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
380         if (!info) {
381                 return_ACPI_STATUS(AE_NO_MEMORY);
382         }
383
384         info->parameters = &this_walk_state->operands[0];
385
386         status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
387                                        obj_desc->method.aml_start,
388                                        obj_desc->method.aml_length, info,
389                                        ACPI_IMODE_EXECUTE);
390
391         ACPI_FREE(info);
392         if (ACPI_FAILURE(status)) {
393                 goto cleanup;
394         }
395
396         /*
397          * Delete the operands on the previous walkstate operand stack
398          * (they were copied to new objects)
399          */
400         for (i = 0; i < obj_desc->method.param_count; i++) {
401                 acpi_ut_remove_reference(this_walk_state->operands[i]);
402                 this_walk_state->operands[i] = NULL;
403         }
404
405         /* Clear the operand stack */
406
407         this_walk_state->num_operands = 0;
408
409         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
410                           "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
411                           method_node->name.ascii, next_walk_state));
412
413         /* Invoke an internal method if necessary */
414
415         if (obj_desc->method.info_flags & ACPI_METHOD_INTERNAL_ONLY) {
416                 status =
417                     obj_desc->method.dispatch.implementation(next_walk_state);
418                 if (status == AE_OK) {
419                         status = AE_CTRL_TERMINATE;
420                 }
421         }
422
423         return_ACPI_STATUS(status);
424
425       cleanup:
426
427         /* On error, we must terminate the method properly */
428
429         acpi_ds_terminate_control_method(obj_desc, next_walk_state);
430         if (next_walk_state) {
431                 acpi_ds_delete_walk_state(next_walk_state);
432         }
433
434         return_ACPI_STATUS(status);
435 }
436
437 /*******************************************************************************
438  *
439  * FUNCTION:    acpi_ds_restart_control_method
440  *
441  * PARAMETERS:  walk_state          - State for preempted method (caller)
442  *              return_desc         - Return value from the called method
443  *
444  * RETURN:      Status
445  *
446  * DESCRIPTION: Restart a method that was preempted by another (nested) method
447  *              invocation.  Handle the return value (if any) from the callee.
448  *
449  ******************************************************************************/
450
451 acpi_status
452 acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
453                                union acpi_operand_object *return_desc)
454 {
455         acpi_status status;
456         int same_as_implicit_return;
457
458         ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
459
460         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
461                           "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
462                           acpi_ut_get_node_name(walk_state->method_node),
463                           walk_state->method_call_op, return_desc));
464
465         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
466                           "    ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
467                           walk_state->return_used,
468                           walk_state->results, walk_state));
469
470         /* Did the called method return a value? */
471
472         if (return_desc) {
473
474                 /* Is the implicit return object the same as the return desc? */
475
476                 same_as_implicit_return =
477                     (walk_state->implicit_return_obj == return_desc);
478
479                 /* Are we actually going to use the return value? */
480
481                 if (walk_state->return_used) {
482
483                         /* Save the return value from the previous method */
484
485                         status = acpi_ds_result_push(return_desc, walk_state);
486                         if (ACPI_FAILURE(status)) {
487                                 acpi_ut_remove_reference(return_desc);
488                                 return_ACPI_STATUS(status);
489                         }
490
491                         /*
492                          * Save as THIS method's return value in case it is returned
493                          * immediately to yet another method
494                          */
495                         walk_state->return_desc = return_desc;
496                 }
497
498                 /*
499                  * The following code is the optional support for the so-called
500                  * "implicit return". Some AML code assumes that the last value of the
501                  * method is "implicitly" returned to the caller, in the absence of an
502                  * explicit return value.
503                  *
504                  * Just save the last result of the method as the return value.
505                  *
506                  * NOTE: this is optional because the ASL language does not actually
507                  * support this behavior.
508                  */
509                 else if (!acpi_ds_do_implicit_return
510                          (return_desc, walk_state, FALSE)
511                          || same_as_implicit_return) {
512                         /*
513                          * Delete the return value if it will not be used by the
514                          * calling method or remove one reference if the explicit return
515                          * is the same as the implicit return value.
516                          */
517                         acpi_ut_remove_reference(return_desc);
518                 }
519         }
520
521         return_ACPI_STATUS(AE_OK);
522 }
523
524 /*******************************************************************************
525  *
526  * FUNCTION:    acpi_ds_terminate_control_method
527  *
528  * PARAMETERS:  method_desc         - Method object
529  *              walk_state          - State associated with the method
530  *
531  * RETURN:      None
532  *
533  * DESCRIPTION: Terminate a control method.  Delete everything that the method
534  *              created, delete all locals and arguments, and delete the parse
535  *              tree if requested.
536  *
537  * MUTEX:       Interpreter is locked
538  *
539  ******************************************************************************/
540
541 void
542 acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
543                                  struct acpi_walk_state *walk_state)
544 {
545
546         ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
547
548         /* method_desc is required, walk_state is optional */
549
550         if (!method_desc) {
551                 return_VOID;
552         }
553
554         if (walk_state) {
555
556                 /* Delete all arguments and locals */
557
558                 acpi_ds_method_data_delete_all(walk_state);
559
560                 /*
561                  * If method is serialized, release the mutex and restore the
562                  * current sync level for this thread
563                  */
564                 if (method_desc->method.mutex) {
565
566                         /* Acquisition Depth handles recursive calls */
567
568                         method_desc->method.mutex->mutex.acquisition_depth--;
569                         if (!method_desc->method.mutex->mutex.acquisition_depth) {
570                                 walk_state->thread->current_sync_level =
571                                     method_desc->method.mutex->mutex.
572                                     original_sync_level;
573
574                                 acpi_os_release_mutex(method_desc->method.
575                                                       mutex->mutex.os_mutex);
576                                 method_desc->method.mutex->mutex.thread_id = 0;
577                         }
578                 }
579
580                 /*
581                  * Delete any namespace objects created anywhere within the
582                  * namespace by the execution of this method. Unless:
583                  * 1) This method is a module-level executable code method, in which
584                  *    case we want make the objects permanent.
585                  * 2) There are other threads executing the method, in which case we
586                  *    will wait until the last thread has completed.
587                  */
588                 if (!(method_desc->method.info_flags & ACPI_METHOD_MODULE_LEVEL)
589                     && (method_desc->method.thread_count == 1)) {
590
591                         /* Delete any direct children of (created by) this method */
592
593                         acpi_ns_delete_namespace_subtree(walk_state->
594                                                          method_node);
595
596                         /*
597                          * Delete any objects that were created by this method
598                          * elsewhere in the namespace (if any were created).
599                          * Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the
600                          * deletion such that we don't have to perform an entire
601                          * namespace walk for every control method execution.
602                          */
603                         if (method_desc->method.
604                             info_flags & ACPI_METHOD_MODIFIED_NAMESPACE) {
605                                 acpi_ns_delete_namespace_by_owner(method_desc->
606                                                                   method.
607                                                                   owner_id);
608                                 method_desc->method.info_flags &=
609                                     ~ACPI_METHOD_MODIFIED_NAMESPACE;
610                         }
611                 }
612         }
613
614         /* Decrement the thread count on the method */
615
616         if (method_desc->method.thread_count) {
617                 method_desc->method.thread_count--;
618         } else {
619                 ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
620         }
621
622         /* Are there any other threads currently executing this method? */
623
624         if (method_desc->method.thread_count) {
625                 /*
626                  * Additional threads. Do not release the owner_id in this case,
627                  * we immediately reuse it for the next thread executing this method
628                  */
629                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
630                                   "*** Completed execution of one thread, %u threads remaining\n",
631                                   method_desc->method.thread_count));
632         } else {
633                 /* This is the only executing thread for this method */
634
635                 /*
636                  * Support to dynamically change a method from not_serialized to
637                  * Serialized if it appears that the method is incorrectly written and
638                  * does not support multiple thread execution. The best example of this
639                  * is if such a method creates namespace objects and blocks. A second
640                  * thread will fail with an AE_ALREADY_EXISTS exception.
641                  *
642                  * This code is here because we must wait until the last thread exits
643                  * before marking the method as serialized.
644                  */
645                 if (method_desc->method.
646                     info_flags & ACPI_METHOD_SERIALIZED_PENDING) {
647                         if (walk_state) {
648                                 ACPI_INFO((AE_INFO,
649                                            "Marking method %4.4s as Serialized because of AE_ALREADY_EXISTS error",
650                                            walk_state->method_node->name.
651                                            ascii));
652                         }
653
654                         /*
655                          * Method tried to create an object twice and was marked as
656                          * "pending serialized". The probable cause is that the method
657                          * cannot handle reentrancy.
658                          *
659                          * The method was created as not_serialized, but it tried to create
660                          * a named object and then blocked, causing the second thread
661                          * entrance to begin and then fail. Workaround this problem by
662                          * marking the method permanently as Serialized when the last
663                          * thread exits here.
664                          */
665                         method_desc->method.info_flags &=
666                             ~ACPI_METHOD_SERIALIZED_PENDING;
667                         method_desc->method.info_flags |=
668                             ACPI_METHOD_SERIALIZED;
669                         method_desc->method.sync_level = 0;
670                 }
671
672                 /* No more threads, we can free the owner_id */
673
674                 if (!
675                     (method_desc->method.
676                      info_flags & ACPI_METHOD_MODULE_LEVEL)) {
677                         acpi_ut_release_owner_id(&method_desc->method.owner_id);
678                 }
679         }
680
681         return_VOID;
682 }